Metarhizium anisopliae as a potential biocontrol agent to suppress the tomato leafminer Phthorimaea absoluta in China.

Background: Phthorimaea absoluta, an invasive pest, has recently become a devastating threat to China's tomato cultivation industry. Chemical insecticides have historically constituted the primary control strategy against this pest, but their intensive application has led to widespread development of resistance in P. absoluta populations. Metarhizium anisopliae presents a promising sustainable alternative for this pest. However, China currently lacks commercially available insecticides specifically targeting this pest, highlighting a critical gap in integrated pest management programs.

Results: In the current study, we evaluated the time-concentration mortality response of P. absoluta larvae and pupae to M. anisopliae QLSMA201102 and examined the ecophysiological characters and potential application areas of this fungus in China using a thermal performance curves model. The results showed that M. anisopliae caused higher cumulative mortality of 100.00% for all the P. absoluta larval instars and pupae at 3.35 × 10 or 3.35 × 10 conidia/mL, with short lethal times and low lethal concentrations. In addition, the ecophysiological characterisation results indicate that this fungus can adapt to a wide range of temperatures, a light/dark cycle and pH. The conidia of M. anisopliae QLSMA201102 also had strong tolerance to UVB light and high temperatures. The potential deployment or application areas prediction revealed high suitability of most parts of China from April to October for this fungus, and consequently it could be used to control P. absoluta in diverse agro-ecosystems in China.

Conclusion: Our results highlight that M. anisopliae has the potential to be developed as a biopesticide for sustainable management of P. absoluta in tomato cropping systems in China. © 2025 Society of Chemical Industry.